I was going to do a round-up of XPS related stuff from WinHEC, but Feng had already done it so, like a true program manager, here's a couple of pointers....
If you're a dev and haven't found it already, you'll want to add Feng's blog to your feeds.
There's also two related Microsoft papers on the WinHEC 2007 Conference Papers page:
- Maximum Performance from XPS Documents — which should be self explanatory
- XPSDrv Filter Pipeline — which covers guidelines and best practice for developers of XPS printer drivers
Enjoy (as I'm learning to say).